U.S. patent application number 11/577109 was filed with the patent office on 2009-02-19 for trocar with obturator having longitudinal through holes for guiding wires.
This patent application is currently assigned to BIOCOMPOSITES LIMITED. Invention is credited to Russell David Waters.
Application Number | 20090048575 11/577109 |
Document ID | / |
Family ID | 33462630 |
Filed Date | 2009-02-19 |
United States Patent
Application |
20090048575 |
Kind Code |
A1 |
Waters; Russell David |
February 19, 2009 |
TROCAR WITH OBTURATOR HAVING LONGITUDINAL THROUGH HOLES FOR GUIDING
WIRES
Abstract
Surgical apparatus includes a trocar and obturator. The trocar
has a hollow cylindrical body with a handle at the proximal end
thereof. The obturator has a solid cylindrical body with a handle
at the proximal end thereof. A central through hole is provided
extending through the body and a slot is provided in the
circumference of the body, extending parallel to the hole. Guide
wires can selectively extend through either the central hole or
along the slot.
Inventors: |
Waters; Russell David;
(Kentsford Cheshire, GB) |
Correspondence
Address: |
SMITH-HILL AND BEDELL, P.C.
16100 NW CORNELL ROAD, SUITE 220
BEAVERTON
OR
97006
US
|
Assignee: |
BIOCOMPOSITES LIMITED
Keele, Staffordshire
GB
|
Family ID: |
33462630 |
Appl. No.: |
11/577109 |
Filed: |
September 22, 2005 |
PCT Filed: |
September 22, 2005 |
PCT NO: |
PCT/GB05/03649 |
371 Date: |
May 16, 2007 |
Current U.S.
Class: |
604/506 ;
604/164.13 |
Current CPC
Class: |
A61B 17/1735 20130101;
A61B 17/3472 20130101; A61B 17/3468 20130101; A61B 2090/08021
20160201; A61B 17/1697 20130101 |
Class at
Publication: |
604/506 ;
604/164.13 |
International
Class: |
A61B 17/34 20060101
A61B017/34 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 13, 2004 |
GB |
0422710.4 |
Claims
1-26. (canceled)
27. Surgical apparatus, the apparatus including a trocar and an
obturator, the trocar including a handle and a hollow body, which
body is beatable so as to extend into an incision in a patient's
body during surgery; the obturator being extendible through the
trocar body, and including an axial through guide hole through
which a guide wire can extend, and a guide formation spaced from
the guide hole, which guide formation can guide a stabilizing
wire.
28. Apparatus according to claim 27 wherein the guide formation
extends substantially parallel to the guide hole to guide a
stabilising wire substantially parallel to and spaced from the
guide wire and the guide hole.
29. Apparatus according to claim 27 wherein the guide formation is
not parallel to the guide hole.
30. Apparatus according to claim 29 wherein the guide formation
extends substantially helically around the obturator.
31. Apparatus according to claim 27 wherein the obturator is a
sliding fit in the hollow body of the trocar.
32. Apparatus according to claim 27 wherein the obturator is
rotatable relative to the trocar.
33. Apparatus according to claim 27 wherein the distal end,
relative to a user of the apparatus, of the obturator is extendable
beyond the distal end of the trocar body, when the obturator is
fully located in the trocar body.
34. Apparatus according to claim 27 wherein the distal end of the
obturator is rounded.
35. Apparatus according to claim 27 wherein a plurality of
formations are provided on the distal end of the trocar body, which
formations are engageable in use against a bone in a patient's
body.
36. Apparatus according to claim 35 wherein the formations are in
the form of teeth spaced circumferentially around the distal end of
the trocar body.
37. Apparatus according to claim 36, wherein the teeth are
chamfered so as to reduce in length radially outwardly.
38. Apparatus according to claim 27 wherein the obturator has a
substantially cylindrical part which is extendible through the
trocar body.
39. Apparatus according to claim 38, wherein the guide hole extends
axially in the cylindrical part.
40. Apparatus according to claim 38 wherein the guide formation
comprises a slot in the circumference of the cylindrical part.
41. Apparatus according to claim 27 wherein the obturator includes
a proximal formation of a size which cannot extend into the trocar
body.
42. Apparatus according to claim 41 wherein a hole is provided in
the proximal formation which is aligned with the guide
formation.
43. Apparatus according to claim 41 wherein the obturator is
rotatable relative to the trocar and the proximal formation is in
the form of a handle to facilitate rotation of the obturator
relative to the trocar.
44. Apparatus according to claim 27 wherein the trocar body is in
the form of an open ended hollow cylinder.
45. A method of surgery, the method including using an apparatus
according to claim 27 passing a guide wire through the guide hole
to engage in a patient's body, and passing a stabilising wire along
the guide formation to engage in the person's body.
46. A method according to claim 45 wherein the guide wire engages
in a bone in the person's body.
47. A method according to claim 46 wherein a hole is drilled in the
bone using a cannulated drill through which the guide wire
guidingly extends.
48. A method according to claim 47 wherein the hole is tapped using
a cannulated device through which the guide wire guidingly
extends.
49. A method according to claim 47 wherein the hole is countersunk
using a cannulated device through which the guide wire guidingly
extends.
50. A method according to claim 47 wherein a cannulated screw is
inserted in the hole, with the guide wire guidingly extending
through the screw and also a tool to turn the screw.
Description
[0001] This invention concerns surgical apparatus, particularly but
not exclusively surgical apparatus usable in the percutaneous
implantation of a compression screw, and also a method of surgery
using such apparatus.
[0002] Internal fixation of fractured bones is often accomplished
with the use of traditional hardware including pins, plates,
screws, rods and wire. The clinical objective of the surgeon is to
realign the bone fragments in anatomical apposition and to maintain
reduction until biological healing has occurred. This is generally
achieved through an open procedure where the fracture site is
surgically exposed to enable relatively easy access to the bone
fragments. However there is a trend towards the use of a more
minimally invasive, percutaneous approach since this reduces pain
and trauma to the patient and helps a speedier recovery.
[0003] The nature of the fracture and the anatomy of the site
dictate to some extent the type of hardware that can be used and
whether or not a simple percutaneous approach is possible. For
highly comminuted fractures multiple pins, screws and/or wires are
usually necessary. For simple fractures, particularly those which
are undisplaced, a percutaneous approach becomes more possible. The
use of compression screws applied across the fracture site is a
popular technique. These devices come in a range of configurations
including headed or headless, cannulated or solid, fully threaded
or partially threaded and with a thread pitch and/or diameter that
can vary from the proximal end to the distal end of the screw. They
are used across a fracture site to pull together the two bone
fragments and hold the fracture surfaces in compression.
[0004] The procedure for inserting the screw accurately within the
bone and across the fracture site involves initially forming the
skin incision followed by the insertion of a guide wire into the
bone under x-ray visualisation. The guide wire defines the track of
the screw. When the guide wire is in the correct position as judged
by the surgeon, a cannulated drill is driven over the said wire to
form a bone tunnel for the subsequent insertion of the screw. If
the screw is not of the self-tapping type then a tap or bone tunnel
dilator may be used prior to screw insertion to form the screw
threaded track. This is often the case if the screw is manufactured
from a polymer or polymer composite material which does not have
the strength to cut into the bone. An effect of all of the
processes of drilling, tapping, dilating, countersinking and
screwing in the screw is to transmit rotational force to the bone
fragments. If these fragments are not held sufficiently firmly then
this torque could result in rotation of the bone fragments relative
to adjacent tissue or to one another. This would be an undesirable
situation.
[0005] According to the present invention there is provided
surgical apparatus, the apparatus including a trocar and an
obturator, the trocar including a handle and a hollow body, which
body is locatable so as to extend into an incision in a patient's
body during surgery; the obturator being extendible through the
trocar body, and including an axial through guide hole through
which a guide wire can extend, and a guide formation spaced from
the guide hole, which guide formation can guide a stabilising
wire.
[0006] The guide formation may extend substantially parallel to the
guide hole to guide a stabilising wire substantially parallel to
and spaced from the guide wire and the guide hole.
[0007] Alternatively the guide formation is not parallel to the
guide hole, and the guide formation may extend substantially
helically around the obturator.
[0008] The obturator is preferably a sliding fit in the hollow body
of the trocar, and the obturator is preferably rotatable relative
to the trocar.
[0009] The distal end, relative to a user of the apparatus, of the
obturator is preferably extendible beyond the distal end of the
trocar body, when the obturator is fully located in the trocar
body. The distal end of the obturator is preferably rounded.
[0010] A plurality of formations are preferably provided on the
distal end of the trocar body, which formations are engageable in
use against a bone in a patient's body. The formations may be in
the form of teeth spaced circumferentially around the distal end of
the trocar body. The teeth are preferably chamfered so as to reduce
in length radially outwardly.
[0011] The obturator preferably has a substantially cylindrical
part which is extendible through the trocar body, and the guide
hole preferably extends axially in the cylindrical part.
[0012] The guide formation preferably comprises a slot in the
circumference of the cylindrical part.
[0013] The obturator preferably also includes a proximal formation
of a size which cannot extend into the trocar body.
[0014] A hole may be provided in the proximal formation which is
aligned with the guide formation. The proximal formation may be in
the form of a handle to facilitate rotation of the obturator
relative to the trocar.
[0015] The trocar body is preferably in the form of an open ended
hollow cylinder.
[0016] The invention also provides a method of surgery, the method
including using an apparatus according to any of the preceding
eleven paragraphs, passing a guide wire through the guide hole to
engage in a patient's body, and passing a stabilising wire along
the guide formation to engage in the person's body.
[0017] The guide wire may engage in a bone in the person's
body.
[0018] A hole may be drilled in the bone using a cannulated drill
through which the guide wire guidingly extends. The hole may be
tapped using a cannulated device through which the guide wire
guidingly extends. The hole may be countersunk using a cannulated
device through which the guide wire guidingly extends.
[0019] A cannulated screw may be inserted in the hole, with the
guide wire guidingly extending through the screw and also a tool to
turn the screw.
[0020] Embodiments of the present invention will now be described
by way of example only and with reference to the accompanying
drawings, in which:--
[0021] FIG. 1 is a side view of surgical apparatus according to the
invention in an assembled condition;
[0022] FIG. 2 is a side view of the apparatus of FIG. 1 in a
disassembled condition;
[0023] FIG. 3 is a perspective view of the proximal end of the
apparatus of FIG. 1 in an assembled condition;
[0024] FIG. 4 is a perspective view of the proximal end of the
apparatus of FIG. 1 in a disassembled condition;
[0025] FIG. 5 is a perspective view of the distal end of the
apparatus of FIG. 1 in an assembled condition; and
[0026] FIG. 6 is a diagrammatic side view of part of an alternative
apparatus according to the invention.
[0027] FIGS. 1 to 5 of the drawings show surgical apparatus 10
suitable for use in percutaneous bone fixation, for example in
implanting a compression screw to join together two bone fragments.
The apparatus 10 comprises a trocar 12 and obturator 14. The trocar
12 comprises a hollow cylindrical body 16 with a handle 18 at the
proximal end of the body 16.
[0028] Engagement formations in the form of a plurality of teeth 20
are provided spaced around the distal end of the body. 16. The
teeth 20 are chamfered such that they slope rearwardly away from
the axis of the trocar 12. The handle 18 has a through hole
corresponding to the interior of the body 16 to enable the
obturator 14 to pass therethrough. The handle 18 includes a first
section 22 which extends transversely from the proximal end of the
body 16, and a second section 24 which extends transversely and
also rearwardly.
[0029] The obturator 14 comprises a solid cylindrical body 26 with
a handle 28 at the proximal end of the body 26. The body 26 has a
rounded distal end 30. A central through hole 32 is provided
extending through the body 26 and handle 28. A slot 34 is provided
in the circumference of the body 26 extending parallel to the
through hole 32. A further hole 36 is provided in the handle 28
aligned with the slot 34. The through hole 32 is of a size to
slidingly accept a guide wire 38. The slot 34 and further hole 36
are of a size to slidingly accept a stabilising wire 40.
[0030] The obturator body 26 is of a size to slidingly and
rotatingly fit within the body 16. The obturator handle 28
comprises a first collar section 42 of a size to abut against the
trocar handle 18, being too large to pass through the interior of
the body 16. The handle 28 also comprises a transverse section 44
at the proximal end of the collar section 42, to facilitate
rotation of the obturator 14.
[0031] The apparatus 10 can be used for example to perform a
surgical procedure to repair a fractured scaphoid. The procedure
involves the percutaneous implantation of a cannulated compression
screw to hold in apposition the bone fragments and facilitate bony
union, and will now be described.
[0032] An incision is made over the proximal pole of the scaphoid.
The obturator is fully located in the trocar as shown in FIG. 1,
and this combination is advanced through the skin and soft tissue,
until the teeth 20 on the trocar 12 engage the cortical surface of
the first bone fragment. The rounded distal end 30 of the obturator
14 and the chamfered teeth 20 enable percutaneous advancement of
the combined trocar 12 and obturator 14 without snagging or tearing
of soft tissue. Forward pressure on the trocar 12 maintains
fracture reduction while the teeth 20 bite into the cortical bone
to prevent slipping of the apparatus 10 on the bone surface. The
position on the bone surface adjacent the through hole 32 defines
the subsequent position of entry of the compression screw.
[0033] The guide wire 38 is then introduced through the hole 32
under x-ray visualisation. The guide wire 38 may be rotated and
drilled into the bone fragments. The obturator 14 is then rotated
relative to the trocar 12 as required to locate the stabilising
wire 40 in a required position. The wire 40 is then introduced
through the further hole 36 and along the slot 34 to engage in the
two bone fragments. The obturator 14 is removed from the trocar 12
and hence patient. A cannulated drill is passed over the guide wire
38 through the trocar 12 to form a bone tunnel within the bone
fragments. In certain circumstances it may be that the trocar 12 is
also removed prior to drilling. The rotational motion of the drill
conveys a rotational force to the bone fragments which could
potentially result in relative misalignment. Such rotation is
substantially prevented by the stabilising wire 40.
[0034] If the screw to be inserted is a polymeric based device as
opposed to a metallic self tapping screw, a tap or bone tunnel
dilator will then be inserted over the guide wire 38 to form a
track through the screw. If required the hole may also be
countersunk. The cannulated compression screw can then be inserted
over the guide wire 38 to pull together and hold together the bone
fragments in an anatomical position. A cannulated tool to rotate
the screw may be inserted over the guide wire 38. The guide wires
38, 40 are then removed prior to wound closure.
[0035] There is thus described surgical apparatus and also a method
of using such apparatus, which permits percutaneous implantation of
a bone compression screw whilst significantly reducing the
possibility of misalignment of bone fragments due to rotational
forces caused for instance by drilling. The apparatus is of a
conventional format and can thus be used in a normal manner without
any significant extra surgical steps. The apparatus can also be
readily manufactured using conventional techniques.
[0036] FIG. 6 shows a further obturator 50 which is similar in most
respects to the obturator 14. However, with the obturator 50 a slot
52 is provided in the circumference of the obturator body 54, which
slot 52 is not parallel to the central through hole which can
receive a guide wire 38. In this instance the slot 52 defines a
gentle helix around the body 54. In use a stabilising wire guided
by the slot 52 will enter and exit the apparatus inclined relative
to the guide wire 38.
[0037] Various other modifications may be made without departing
from the scope of the invention. For example the shape of the
components may be changed. A plurality of stabilising wires could
be used, and in different alignments.
[0038] Whilst endeavouring in the foregoing specification to draw
attention to those features of the invention believed to be of
particular importance it should be understood that the Applicant
claims protection in respect of any patentable feature or
combination of features hereinbefore referred to and/or shown in
the drawings whether or not particular emphasis has been placed
thereon.
* * * * *